Inspiratory muscle training (IMT) is becoming more popular in sporting populations as
contentious issues associated with the magnitude of its effect as an ergogenic training
aid are gradually dispelled. The main reason for this is the increasing good practice in
controlled intervention studies particularly through the use of appropriate outcome
measures, for example time trial performance, but also the work done to identify
potential mechanisms such as the blood flow redistribution model. The purpose of this
thesis is to further improve the benefits afforded by IMT through the development and
evaluation of new technologies. The key aim was to produce technologies that provide
functional relevance to a sporting population by permitting normal, albeit loaded
ventilation to take place in an ambulatory situation. A number of intermediate
objectives have been achieved including the identification of the key limitations of
existing technologies and their application, the development of new methods for the
prescription of a dynamic inspiratory load via a series of human studies i.e. mouth
pressure generation due to inspiratory drive during exercise, 3-Dimensional thoracic
displacement and peripheral thoracic force generation, and the design, manufacture and
evaluation of two new inspiratory muscle training technologies. These are a thoracic
restricting technology that provides true ambulatory loading and a variable mouth
occlusion technology that can be set to load in accordance with the specific pressurevolume
characteristics of an individual. The former (thoracic restricting technology) has
been developed into a first stage prototype and tested on a single subject to assess any
changes to breathing pattern. The results suggest that suitable load location may
minimise any adverse effects and has enabled further theoretical development to take
place. The latter (variable mouth occlusion technology) has been implemented in a
controlled study on a group of healthy male adults to assess its functionality and the
suitability of a specific decaying load. The results suggest that the chosen load may have
been unsuccessful in increasing the work of breathing and that specific aspects of the
functionality require development thus enabling the selection of specific refinements for
future interventions to be identified. The focus of future research is therefore the
practical comparison of these new technologies with existing devices in order to fully
understand the optimisation of inspiratory muscle training.

Description:

A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.